BRENTWOOD — A crackdown on bad drivers along the Highway 4 bypass appears to be working.

Speeding isn’t as common as it used to be and drunken driving has dropped slightly since Brentwood police and the California Highway Patrol beefed up patrols of the heavily trafficked shortcut between Brentwood and Antioch, authorities said.

The city’s officers wrote 317 tickets from June 21 through Aug. 30, more than three times the number they had issued during the same length of time before the crackdown.

Of those citations, 198 were for speeding and other moving violations such as making an unsafe lane change and running a red light.

Police also made two drunken-driving arrests and reported five injury accidents during that period. A sixth collision proved fatal when a woman hit a radar speed sign next to the westbound lane.

By contrast, Brentwood officers wrote 100 tickets from April 11 through June 20, of which 72 were for speeding and other moving violations. They also made five arrests for drunken driving and responded to three injury accidents.

The CHP also issued more citations along the two segments of the bypass it monitors after the crackdown, although the number of speeding tickets declined.

During the 71-day period ending June 20, the CHP issued 210 tickets, including 159 for speeding. There were also two injury accidents, one of which involved a drunken driver.

Though the number of citations issued by the CHP increased by two dozen over the next 10 weeks, the number of speeding tickets dropped to 90, there was just one injury accident, and no cases of driving under the influence.

The two agencies stepped up enforcement after a double fatality in mid-June just west of where the bypass crosses Lone Tree Way.

A westbound pickup truck triggered a chain reaction in which a car veered over the median and into a couple on a motorcycle in the eastbound lane. The driver of the truck, a Utah man, was arrested and charged with causing the deaths of the motorcyclists.

Brentwood police started ticketing in earnest six days later, when it shelled out $7,111 in overtime pay to have additional officers work the section of the bypass within the city’s jurisdiction through the end of the month.

Usually, only one person is assigned to the beat that includes the bypass.

For nine days, however, the agency paid 16 hours of overtime a day during the workweek and 16 hours on weekends.

The State Route 4 Bypass Authority followed suit in late July, putting aside $7,400 for 100 hours of overtime coverage by Brentwood police over the course of the next month.

The agency, which has overseen the design, funding and construction of the bypass, is expected to approve an additional 100 hours at its meeting today.

In addition, it has ordered stationary signs warning passers-by to drive safely.

The bypass authority, county and cities of Brentwood and Oakley also have been taking turns putting out two radar speed signs at a time.

CHP spokesman Tom Maguire is optimistic that the push for safety will change drivers’ behavior.

“I would say that the message has crept into some people’s heads,” he said. “Are there people who still need to get the message? Yes. We want everybody out here to get (it), and ultimately we will.”

But for those who have no intention of changing their ways, Maguire has a promise.

“If you’re going to do something that causes injury … we will find you,” he said. “You’re not going to go unscathed.”

Rowena Coetsee is a staff writer who has been covering all the news that's fit to print since beginning her career at the Palo Alto Times. A graduate of UC Santa Barbara, she joined Bay Area News Group as a features writer and these days works a beat in East Contra Costa County that includes city government, K-12 education and a fire district.

In addition to evacuating 10 neighboring homes, deputies restricted pedestrian and vehicle traffic in the area while the sheriff's office bomb squad "safely disposed" of the explosives, officials said.